Thermal interface material and semiconductor device incorporating the same

ABSTRACT

A thermal interface material ( 13 ) and a semiconductor device ( 10 ) using the thermal interface material are provided. The thermal interface material is formed as a sheet, comprising a pair of cured sheets ( 131 ) and a reinforcement member ( 132 ) arranged between the cured sheets. The reinforcement member, which improves the physical strength of the thermal interface material, is made of a material chosen from the group consisting of woven copper fabric, woven copper cloth, woven stainless fabric, woven stainless cloth, and any appropriate combination of the aforementioned materials.

FIELD OF THE INVENTION

The present invention relates to a thermal interface material which is interposable between a heat-generating electronic component and a heat dissipating component, and it also relates to a semiconductor device using the thermal interface material.

DESCRIPTION OF RELATED ART

With the fast development of the electronic industry, advanced electronic components such as CPUs (central processing units) are being made to have ever smaller sizes and ever quicker operating speeds. During operation of the advanced electronic components, much heat is generated. In order to ensure good performance and reliability of the electronic components, their operational temperature must be kept within a suitable range. Generally, a heat dissipating apparatus such as a heat sink or a heat spreader is attached to a surface of the electronic component, so that the heat is transferred from the electronic component to ambient air via the heat dissipating apparatus. However, the contact surfaces between the heat dissipating apparatus and the electronic component are rough and therefore are separated from each other by a layer of interstitial air, no mater how precisely the heat dissipating apparatus and the electronic component are brought into contact; thus, the contact resistance is relatively high. A thermal interface material is preferred for being applied to the contact surfaces to eliminate the air gaps between the heat dissipating apparatus and the electronic component in order to improve heat dissipation.

The thermal interface material applied increases the heat dissipation efficiency of the heat dissipating apparatus. However, if the thermal interface material is in the form of a sheet or a pad, it is generally required be cut into smaller pieces in accordance with specific application requirements. Furthermore, the thermal interface material is under the load of the heat dissipating apparatus. It is therefore important to improve the physical strength of the thermal interface material.

SUMMARY OF THE INVENTION

The present invention relates, in one aspect, to a thermal interface material. The thermal interface material comprises a pair of cured sheets and a reinforcement member interposed between the cured sheets, wherein the reinforcement member is made of a material chosen from the group consisting of woven copper fabric, woven copper cloth, woven stainless fabric, woven stainless cloth and any appropriate combination of the aforementioned materials.

The present invention relates, in another aspect, to a semiconductor device using the thermal interface material. The semiconductor device includes a heat generating electronic component, a heat dissipating component that dissipates heat generated by the heat-generating electronic component, and the thermal interface material, wherein the thermal interface material is sandwiched between the heat-generating electronic component and the heat dissipating component.

Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present thermal interface material can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present thermal interface material. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a perspective view of a thermal interface material in accordance with an embodiment of the present invention; and

FIG. 2 is a side view of a semiconductor device using the thermal interface material of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a perspective view of a thermal interface 13 material in accordance with an embodiment of the present invention. The thermal interface material 13 being in the form of a cured sheet has a thickness in the range of from 25˜500 μm, but the thickness may be varied between sections depending upon the requirements of intended heat transfer application. The thermal interface material 13 includes a pair of cured sheets 131 and a layer of reinforcement member 132 which is incorporated as an interlayer between the cured sheets 131.

The cured sheets 131 are made of a room temperature vulcanizing silicone elastomer, with zinc oxide powder having an average particle size in the range of 0.1˜5 μm being dispersed in the silicone elastomer. For example, the filled zinc oxide powder may have an average particle size of 0.1 μm, 0.5 μm, 1 μm, 3 μm, or 5 μm. The silicone elastomer is vulcanized under the room temperature. After being cured, the thermal interface material 13 can be used with a temperature in the range of from −50° C. to +200° C. The room temperature vulcanizing silicone elastomer has excellent electrical insulation properties and thus is compatible with many metallic or nonmetallic materials. The zinc oxide powder dispersed in the silicone elastomer improves thermal conductivity and dielectric properties of the thermal interface material 13.

The reinforcement member 132 interposed between the cured sheets 131 is made of a material chosen from the group consisting of woven copper fabric, woven copper cloth, woven stainless fabric and woven stainless cloth, and any appropriate combination of the aforementioned materials. These materials are suitable for the reinforcement member 132 as they have an excellent physical and mechanical property. As a result the physical strength of the thermal interface material 13 as a whole is greatly improved. This facilitates a die cutting process through which the thermal interface material 13, as originally formed as a single sheet, is cut into small pieces for specific applications. Due to the presence of the reinforcement member 132, the cured sheets 132 of the thermal interface material 13 are effectively prevented from cracking or breaking apart during the die cutting process. In addition, the materials which make up the reinforce member 132 have good heat conduction, so that the heat-transfer efficiency of the thermal interface material 13 can be improved.

Referring to FIG. 2, a semiconductor device 10 using the thermal interface material 13 is shown in a side view. The semiconductor device 10 includes a heat generating electronic component 11 such as a CPU, a heat dissipating component 12 such as a cold plate, a heat spreader or a heat sink for dissipating heat generated by the heat-generating electronic component 11, and the thermal interface material 13 sandwiched between the heat-generating electronic component 11 and the heat dissipating component 12. In this embodiment, the heat dissipating component is a heat sink comprising a plurality of fins (not labeled).

The heat-generating electronic component 11, which is positioned on a printed circuit board (PCB) or a substrate 15, has a heat emitting surface 111 opposite to the substrate 15. The heat dissipating component 12 has a heat absorbing surface 121 facing to the heat emitting surface 111 of the heat-generating electronic component 11. The thermal interface material 13 is sandwiched between the heat emitting surface 111 of the heat-generating electronic component 11 and the heat absorbing surface 121 of the heat dissipating component 12 to provide a thermally conductive path therebetween. A locking device 14 such as a spring clip is provided to secure the heat dissipating component 12 to the heat-generating electronic component 11 to ensure the thermal interface material 13 intimately contacts with the heat emitting surface 111 and the heat absorbing surface 121.

It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A thermal interface material comprising: a pair of cured sheets; and a reinforcement member interposed between the cured sheets, wherein the reinforcement member is made of a material chosen from the group consisting of woven copper fabric, woven copper cloth, woven stainless fabric, woven stainless cloth, and any appropriate combination of the aforementioned materials.
 2. The thermal interface material of claim 1, wherein the thermal interface material is formed as a sheet and a thickness thereof is in the range of 25˜500 μm.
 3. The thermal interface material of claim 1, wherein the cured sheets are made of a room temperature vulcanizing silicone elastomer, with zinc oxide powder being dispersed in the silicone elastomer.
 4. The thermal interface material of claim 3, wherein an average particle size of the zinc oxide powder is in a range of 0.1˜5 μm.
 5. A semiconductor device comprising: a heat generating electronic component; a heat dissipating component that dissipates heat generated by the heat-generating electronic component; and a thermal interface material attached between the heat-generating electronic component and the heat dissipating component, wherein the thermal interface material includes a pair of cured sheets and a reinforcement member arranged between the cured sheets, wherein the reinforcement member is made of a material chosen from the group consisting of woven copper fabric, woven copper cloth, woven stainless fabric, woven stainless cloth, and any suitable combination of the aforementioned materials.
 6. The semiconductor device of claim 5, wherein the thermal interface material is formed as a sheet and a thickness thereof is in the range of 25˜500 μm.
 7. The semiconductor device of claim 5, wherein the cured sheets are made of a room temperature vulcanizing silicone elastomer, with zinc oxide powder being dispersed in the silicone elastomer.
 8. The semiconductor device of claim 7, wherein an average particle size of the zinc oxide powder is in a range of 0.1˜5 μm. 